A “Fixed Wireless Terminal” (FWT) is a device that can communicate wirelessly with the Radio Access Network of a cellular network operator in much the same way as a standard mobile device, e.g. a cellular telephone, smartphone, USB dongle and the like. It uses standard authentication mechanisms to connect to the cellular network, e.g. using a Universal Integrated Circuit Card (UICC) or Subscriber Identity Module (SIM) card. The FWT is fixed in the sense that it is not intended to be carried around by a person. In practice, its mobility may be constrained by the need for access to a power supply, and/or by its intended purpose. However, whilst a FWT may be fixed to a building (inside or out), it may also be located, for example, on a vehicle (bus, car) or train. The FWT provides an access point (to the cellular network) for user devices. The FWT will typically use WiFi to communicate wirelessly with these user devices.
In regions with limited copper (wire) availability for telecommunication services, the FWT offers an efficient and relatively low cost solution to the problem, providing a communications “hotspot”. As long as users are within range of a FWT they are able to access telecommunication services. Another interesting possibility afforded by FWTs is the connection of legacy (GSM and 3G) terminals to high capacity Long Term Evolution (LTE) and High Speed Packet Access (HSPA) networks. In many regions it will take a considerable time for consumers to acquire LTE or HSPA enabled terminals, and the FWT will allow cellular network operators to take advantage of the backhaul capability and flexibility of LTE and HSPA infrastructure in the meantime. In such a scenario, the FWT provides an interface between the WiFi access and the LTE or HSPA access network. This is illustrated schematically in FIG. 1.
The 3GPP specification 23.402 and WiFi Alliance Hotspot 2.0 are concerned with fixed broadband connectivity to a WiFi access point. Access control and roaming in a WiFi access environment tends to be built around Wireless Internet Service Provider roaming (WiSPr) and emerging technologies using Extensible Authentication Protocol (EAP) Subscriber Identity Module (SIM)/Authentication and Key Agreement (AKA) authentication. Unless new functionality is introduced, these solutions will be inefficient for FWTs having mobile access broadband connectivity. Individual users behind the FWT are not seen by the mobile access network as they are hidden behind a NAT inside the FWT. Possible alternative solutions involve web login procedures and/or tunneling between the user devices and some central (e.g. Virtual Private Network (VPN)) server. However, such solutions are likely to be complex to implement and will not integrate well with existing mobile network architectures and policy control (e.g. for charging and Quality of Service (QoS) purposes).